Flotation of minerals



wvood. Notable examples of processes and I narrate snares DUNCAN w. ramnson, or DoUemsToN, NEW YORK, AND HENRY L. WOOLFENDEN,

1 or DENVER, COLORADO.

career FLOTATION 0 1E MINMLS.

No Drawing.

To all whom it may concern:

Be it known that we, DUNCAN W. PAT- TERSON and HENRY L. WOOLFENDE citizens of the United States, and residents of Douglaston, Long Island, Queens County, in the tion, and is particularly directed to theemployment in such processes of a new flotative agent.

The substance which we employ as such agent is derived from fibrous vegetable matter, and is contained in the fluid product obtained in well known types of commercial processes for treating such vegetable matter, particularly wood, to separate from the fibres various soluble and suspensible. elements by means of suitable solvents, chemical reagents, or both.

In some of these processes a substance or substances carried by the fluid product is primarily desired commercially, as in the extraction of licorice from licorice root. In others, the chief object is to free the fibres, as in the manufacture of paper pulp from extracts of the type indicated are afforded in the commercial treatment of licorice root. This fibrous vegetable substance is first treated with water which dissolves the soluble principle in the root, the solution containing the gummy frothing substance which we have ascertained to be particularly adapted for use as a flotative agent.

In practice it has been found desirable to subject the root to two or more fresh charges of the solvent, resulting in a number of separate solutions derived from the same root;

but any or all of such solutions will be generally referred to herein as constituting the primary extract of licorice roots After extraction by solution is completed the root is subjected to chemical action by one of several methods, generally known as digesting processes, which are commonly employed in the reduction of wood to paper pulp, the sulfite, sulfate and soda methods being most common. The fluid product of the digesting process also contains the gummy substance which we have ascertained Specification of Letters Patent. Patented Apr. 111, 11922.

Application filedNovember 9, 1920. Serial No. 422,782.

to be particularly adapted for use as a flotat1ve agent, and will be herein feferred to as the secondary extract of licorice root.

Other examples of processes in which our improved flotative agent is produced are afforded in the manufacture of paper pulp from wood, the best known methods for this purpose being indicated above.

The fluid products obtained from the digesting of the wood are generally referred to as black liquors and contain our new gummy flotative agent. It is of course understood that in carrying out this type of process for our purposes, the suitability of the residual fibre for use as paper pulp is not essential; and we have found that our gummy flotative agent is best obtained by this method from woods containing a substantial amount .of gummy matter.

The fluid productv obtained from the digesting of fibrous material by chemical reagents in processes of the type last indicated is generally referred to in the paper pulp making industry as black liquor, a term which will be employed herein to indicate generally the fluid product of this type of process regardless of the particular nature of the fibrous vegetable material employed. It is noted that the secondary extract of licorice root above referred to is properly a black .liquor.

and we have ascertained that this substance I is particularly adapted for use as a flotative agent. The substance may be prepared for use by concentrating the extracts above described through evaporation to either a thick fluid or a solid, as convenience in employing the agent in flotation may dictate.

It is of course understood that other methods of preparation of the gummy substance for use from the above extracts may be employed, or that inert elements of the extracts may be removed, within the scope of our invention.

Our new flotative agent may be introduced into the ore at any desired point in the flotation process, either at the grinding v Our new flotative agent, which is identhe process without seriously checking the generation destroying the froth already formed, a distinct advantage over other froth-producing agencies. We have also found that there substantially less danger of destruction of froth by unemulsified selective oil, such as coal tar, a not uncommon occurrence in pres entprocesses generally referred to as raw oil effect, our improved agent not being ser ously affected in its froth-producing qualities by the presence of raw oil within the limits of usual commercial practice.

Moreover, a froth is produced very rapidly with our agent, as compared with the relatively slow process necessary when oil or similar reagents are used. Ne have also found that the froth produced is very readily broken down. These characteristics are valuable in materially increasing not only the speed of the process, but also in eliminating delays and inefficient operation caused by damage to or destruction of the froth.

Our agent may be employed either alone or in combination with other flotative agents, either those primarily employed for their selective affinity for metalliferous particles, such as coal tar; those employed primarily for their froth-producing characteristics, such as pine oil, or those which combine both these features, such as the various established combinations of selective and flotative agents employed by different users of the process, and agents such as X-cake (alpha-naphthylamin) which also combine the two properties.

Our frothing agent produces a particularly strong, clean froth with very little tendency to collect gangue, even when the agent is employed in excessive quantities. Owing to this fact, the amount of our agent employed in the process varies materially with the nature of the ore and the proportion of metalliferous material therei'n, since we are not restricted materially by the danger of destroying the froth through employing an excessive amount of the agent, a danger encountered in prior processes which renders the recovery from certain ores hearing a large proportion of metalliferous ma-- terial relatively ineflicient.

In general, a smaller proportion of our agent is required where it is used in combination with other flotative agents, particularly where such agents have substantial froth-producing characteristics, than where it is used alone or with substances having relatively slight capacity for producing froth. v

We have found that we employ as little as one or two pounds of the dry agent to the ton of dry ore incombination with other flotation agents, while we may emplovtwentyfive pounds or more under suitable conditions, these quantities being given for purposes of illustration only.

of froth, and especially withouttallic substances While we have described our flotative agent as contained in extracts, it will be understood that we contemplate the employment of this substance regardless of the method by which it is obtained, the substance being the froth-producing constituent of the fluid product from the above mentioned commercial processes, readily recognized physically when in solution by its more or less gummy, mucilaginous character.

In certain of the claims we have employed the expression non-aqueous content of black liquor, licorice extract, or secondary licorice extract. his to be understood that by this term we do not mean that the flota tive agent is necessarily provided or employed in dry form, since under some circumstances suflicient water to render the substance fluid is of great assistance in rapid intermixture and eliminating a tendency to produce lumps.

We have herein described our invention in its application to a flotation process for extracting metals, since our improved flotative agent has been found in practice to be peculiarly efficient in this particular field; but our invention is not necessarily limited to this specific application of the flotation process, as flotation is also employed for the segregation or extraction of various non-meand our invention is equally applicable to the latter.

We claim:

1. The method of effecting the concentration of minerals by flotation which comprises adding to the mineral bearing ore a small amount of the gummy frothing agent as constituted in black liquor and subjecting the resulting mixture to a flotation operation.

2. The method of effecting the concentration of minerals by flotation which comprises adding'to the mineral bearing ore a small amount of the gummy frothing agent as constituted in licorice extract and subjecting the resulting mixture to a flotation operation.

3. The method of effecting the concentration of minerals by flotation which com prises adding to. the mineral bearing ore a small amount of the gummy frothing agent as constituted in the secondary extract of licorice root and subjecting the resulting mixture to a flotation operation.

4; The method of effecting the concentration of minerals by. flotation which comprises adding to the mineral bearing ore a tion of minerals by flotation which comprises adding to the mineral bearing ore a small amount of the gummy frothing agent as constituted in the secondary extract of licorice root and a separate agent having a marked selective aflinity for metalliferous particles, and subjecting the resulting mixture to a flotation operation.

7 The method of effecting the concentration of minerals by flotation'which com- ,prises adding to the mineral bearing ore a small amount of the gummy frothing agent as constituted in black liquor and a separate agent having marked (froth-producing characteristics, and subjecting the resulting mixture to a flotation operation.

8. The method of effecting the concentration of minerals by-flotation which comprises adding to the mineral bearing ore a small amount of the gummy frothing agent as constituted in licorice extract and a separate agent having marked froth-producing characteristics, and subjecting the resulting mixture to a flotation operation.

9. The method of effecting the concentration of minerals by flotation which comprises adding to the mineral bearing ore a small amount of the, gummy frothing agent as constituted in the secondary extract of licorice root and a separate agent having marked froth-producing characteristics, and subjecting the resulting mixture to a flotation operation.

10. .The method of effecting the concentration of minerals by flotation which comprises adding to the mineral bearing ore a small amount of the gummy .frothing agent as constituted in black-liquor and an agent having marked selective and flotative characteristics, and subjecting the resulting mixture to a flotation operation. 7

11. The method of effecting the concentration of minerals by flotation which comprises adding to the mineral bearing ore a small amount of the gummy frothing agent as constituted in licorice extract and an agent having marked selective and flotative v characteristics, and subjecting the resulting mixture to a flotation operation. 12. The method of effecting the concentration of minerals by flotation which comprises adding to! the mineral-bearing ore a small amount ofa gummy frothing agent as constituted in the secondary extract of licorice root and an agent having marked selectiveand flotative characteristics, and subjecting the resulting mixture to a flotation operation.

13. The method of effecting the concentration of minerals" by flotation which comprises the introduction into the mineral bearing ore of a flotative agent including a small amount of the non-aqueous content of black liquor, and subjecting the resulting mixture to a flotation operation.

14. The method of effecting the concentration of minerals by flotation which comprises the introduction into the mineral bearing ore of a flotative agent including a small amount of the non-aqueous content of licorice extract, and subjecting the resulting mixture to a flotation, operation.

15. The method of effecting the concentration of minerals by flotation which comprises the introduction into the mineral bearing ore of a flotative agent including a small amount of the non-aqueous content of the secondary extract of licorice root, and subjecting the resulting mixture to a flota tion operation.

16. A. flotation process which comprises adding to the substance treated a small amount of the gummy frothing agent as constituted in black liquor, and subjecting the resulting mixture to a flotation operation.

17 A flotation process which comprises adding to. the substance treated a small amount of the gummy frothing agent as constituted in licorice extract, and subjecting the resulting mixture to a flotation operation.

18. A flotation process the introduction into the substance to be treated of a flotative agent. including a small amount ofthe non-aqeous content of black liquor, and subjecting the resulting mixture to a flotation operation.

19. A flotation process which comprises the introduction into the substance to be treated ofa flotative agent including asmall 6 which comprises amount of the non-aqueous'content of. licorice extract, and subjecting the resulting mlxture to a flotation operation.

Signed at New York city, in'the county of New York and Stateof New York, this 22nd day of October, A. D. 1920.

; DUNCAN W. PATTERSON. HENRY L. WOOLFENDEN. 

